Niki put up a load of pictures on Facebook (TFSI Tuning) demonstrating the differences (will need to search on a PC to find it).
Obvious signs of a fake were the sticker on the box looking distinctly sh*t i.e. very basic and not having a barcode. The billet body of the fakes had 4 holes compared to the genuine which has 3 (perhaps the copy was based on an old design?). The brass piston on the fakes had a very poor finish compared to the genuine item too.
As for the old versions, I believe it had a different piston and plunger, and they may have been a different colour but not 100% sure.
To be honest I would just save up the cash for a new one from AMD